Railway coupler guard arm



April 14, 1959 L. E. FURNISS RAILWAY COUPLER GUARD ARM 2 sheets-sheet 1Filed Dec. 8. 1954 INVENTOR' LQIPEE ELM/V MEN 5Q APril14,1}959 L.aFLvRNlss' 2,881,927

RAILWAY COUPLER GUARD ARM Filed Dec. 8. 1954 2 Sheets-Shee t 2 INVENTORUnited States Patent RAILWAY COUPLER GUARD ARM Loree Elwyn Furniss,Groveport, Ohio, assignor to The Buckeye Steel Castings Company,Columbus, Ohio I A Application December 8, 1954, Serial No. 473,882

4 Claims. (Cl. 213-151) The present invention relates to railwaycouplers and to improvements in the guard arm portion of the couplerandmore specifically pertains to the provision of a surface on the innerface of the guard arm so as to avoid the development of destructivestresses in the coupler head during some operating conditions.

The guard arm of existing couplers has been so shaped that it ispossible for a partly closed knuckle of one coupler to be wedged betweenthe nOse of a closed knuckle on another coupler and the inner face ofthe guard=arm of the second coupler as the two couplers move toward eachother. The wedging action of the partly closed knuckle as it is thrustbetween the nose of the knuckle of the other coupler and the guard armthereof acts outwardly on the guard arm and outwardly on the knuckleside of the coupler head producing stresses within the coupler headhaving the closed knuckle. The extent of such stresses is dependent onthe magnitude and direction of two forces one applied at the inside ofthe guard arm urging it laterally outward and the other force applied tothe knuckle side of the coupler head through the closed knuckle urgingthe knuckle side of the coupler head laterally outward. These forces aredeveloped as a result of the impact of one coupler with the other as tworailway vehicles move toward each other or as one vehicle moves towardsa standing car or the like. The stresses developed in the coupler headhaving the closed knuckle as a result of such an impact force have beenfound to be sufiicient to cause a break in the coupler head extendingrearwardly of the contour in the vicinity of the longitudinal centerline of the coupler.

A further disadvantage takes place with a prior type of coupler when theknuckle thereof is in a partly closed condition as it moves into impactengagement with an existing coupler having the knuckle thereof in theclosed position. One of the two forces developed upon impact engagementof the two couplers is at right angles to the contacting surfaces of thenose portions of the knuckles and the other force is perpendicular tothe contacting surfaces between the heel of the partly closed knuckleand the inner side face of the guard arm. These two forces intersect insuch a position that there is no resulting force which would tend tobring the couplers into a more generally aligned relationship withrespect to each other. A stable condition results and the impact forcesare absorbed by the couplers while they remain in angularly relatedpositions. Accordingly the stresses set up as a result of the impactforces are not well distributed throughout the coupler heads.

It is accordingly an object of the present invention to provideimprovements in the shape of the guard arm portion of a railway couplerso that a resulting force will be developed when a partly closed knuckleof one coupler moves into engagement with another coupler having theknuckle in the fully closed position with such resulting force acting ina direction to horizontally shift the two couplers so that the stemsthereof are moved towards alignment and to provide clearance at theinner face of the guard arm of a coupler so that the heel portions ofboth knuckles may engage the respective guard arms on more generallytransverse surfaces to distribute the stresses within the coupler headsand accordingly reduce the bending stresses in the contour portion ofthe coupler head to avoid the development of rupturing stresses whichhave in some instances in the past caused a breaking of the couplerhead.

Another object of the invention is to provide improvements in the shapeof the inner face of the guard arm of an interlocking coupler so as toreduce the Wedging action when the nose of the knuckle of one couplerengages the nose of the knuckle of another coupler and to provide a moregenerally transverse abutting surface for the heel portions of theknuckles so that the forces developed during impact engagement of thetwo couplers will be transferred from the heel portions of the knucklesto the abutment shoulders thereby reducing the bending stresses and atthe same time applying the forces to additional portions of both couplerheads.

A still further object of the invention is to provide improvements inthe surface of the inner face of the guard arm of an interlockingcoupler so that the heel of a partly closed knuckle moving intoengagement with the improved surface will set up a resulting force incooperation with the engagement of the nose of the partly closed knuckleto develop an unstable condition tending to shift the couplers towardpositions where their longitudinal centers are in more general alignmentto position the couplers for inter-engagement at a plurality of pointsor zones whereby the total force of the impact is distributed in both ofthe coupler heads and applied principally as compressive stresses.

Other objects and features of the invention will be appreciated andbecome apparent to thOSe skilled in the railway coupler art as thepresent disclosure proceeds and upon consideration of the accompanyingdrawings and the following detailed description wherein a railwaycoupler exhibiting the invention is disclosed.

In the drawings:

Fig. 1 is a plan view of an interlocking coupler embodying theinvention.

Fig. 2 is an enlarged fragmentary sectional view of the guard arm sideof the coupler taken on the line 2-2 of Fig. 1.

Fig. 3 is an enlarged fragmentary plan view illustrating in greaterdetail the improved characteristics of the guard arm and guard armprojection.

Fig. 4 is a diagrammatic view illustrating the manner in which aresulting force is developed to provide an unstable condition when twocouplers exhibiting the invention move into engagement.

Fig. 5 is a diagrammatic plan view of two couplers embodying theinvention showing a condition which follows the relationship depicted inFig. 4.

Fig. 6 is a view similar to Fig. 4 illustrating the stable condition oftwo conventional interlocking couplers as they move into engagement.

Referring to the drawings there is shown at 10 a coupler head of theinterlocking type which is provided with a knuckle 12 mounted forpivoting movement about a vertically disposed knuckle pin 14. Thecoupler car ries a guard arm 16 and an aligning wing 17 having a pockettherein is provided at the other side of the knuckle. The major portionof the contour 18 is of the same shape as that of existing interlockingType F couplers and a shelf 19 extends forwardly of the lower portion ofcoupler head below the contour 18 in a manner that is known in the art.The nose 21 of the knuckle remains unchanged and the heel portion 22 isof standard construction.

The invention pertains to changes in the inner face of Patented Apr. 14,1959 ass-1,927

the'guard-arm. 16 in the vicinity of the guard arm projection 23. Theinner surface of the guard arm and guard arm projection are formed tohave a concave cylindrical surface 26 forwardly of the couplingv line 25and having a:radius,R--.Which isapproximately equal-to the radiusforming the convex cylindrical surface of the heel 22 of they knuckle12. and is generated about a vertical axis positioned laterally ofthe-knuckle at such a distance that the.heel of a partly or fully closedknuckle cannot bear against thisconcave surface 26 when the knuckle nose21 is in contact with the nose of an opposing closed knuckle. In oneembodiment the radius R amounts to one and three-quarterinches generatedabout a vertical axis positioned six and fifteen-sixteenth incheslaterally of the center line of the coupler head as indicated at D inFig; 3; A verticallyextending forward facing shoulder 32. is provided bythe cylindrical surface in the area where it.joins; the contour properand this shoulder is substantially transverse to the longitudinal axisof the coupler head. The juncture between the shoulder 32 andthe'contour forms a vertically extending ridge 27. This cylindricalsurface 26 extends to the area indicated at 28 where the arcuate surfacemerges with a substantially straight surface 29 which continues towardsthe nose portionof the guard arm. The location of the ridge 27 remainsunchanged over existing couplers of this type. In oneembodiment thecorner 27 is positioned laterally of the 'center line of the couplerhead at six and fifty-seven sixty-fourth inches. Thus the center aboutwhich the concave surface 26 is generated is positioned a greaterdistance from the center line of the coupler head than the lateraldisplacement of the ridge 27. Accordingly the cylindrical surface formsthe forward facing shoulder 32 in the-area adjacent the ridge 27. Theshape of the inner surface of a corresponding portion of the known TypeF coupler is indicated by the phantom line 31 in Fig. 3 and itwill' beobserved that the shoulder 32 adjacent the corner 27 is vertical andsubstantially at right angles to the longitudinal axis of the couplerhead 10. While the change in this portion of the contour of the couplerappears to be of a minor character new and advantageous resultsare'provided as hereinafter described.

The utility of the guard arm surfaces 26, 29 and 32 of a couplerembodying the present invention will be more apparent upon considerationof Figs. 4 and 5. The couplers shown in Fig. 4 represent a conditionwhich is developed upon contact as two couplers move into engagementwhen the coupler on the right has its knuckle in the fully closedposition and when the knuckle on the coupler at the left is in apartially closed position. The nose of the partially closed knuckleengages the nose of the fully closed knuckle. The heel of the partiallyclosed knuckle engages the ridge 27 of the guard arm of the coupler on.the right. The coupler stem 11 of one coupler is thereby angularlydisplaced with respect to the stem 11 of the other coupler and a line 36extending between the two butt bearing surfaces of the coupler stemsrepresents the direction at which'the impact force is applied to the twocouplers. Theline 36 is angularly displaced from the longitudinal centerline of both couplers. The nose of the partly closed knuckle engages thenose of the coupler carrying the fully closed knuckle at a point or areaindicated at 37. The heel portion of the partly closed knuckle engagesthe ridge of the guard arm of the coupler at the right in Fig. 4 in azone of the knuckle indicated at 38. The force line 41 is at rightangles to the contacting surfaces of the nose portions. The force line42 is perpendicular to the contacting surfaces at 38. These lines 41 and42 intersect at 43. This point of intersection is displaced laterally ofthe line 36. Accordingly a resulting force is developed to move thecouplers towards a more aligned relationship than that shown in Fi'gr4and to move the partially closed knuckle towards a ,closed position.Thus an unstable condition of the couplersexis'ts;

The resultingforceis in such a directionasto shift the couplers towardsthe aligned condition and the partly closed knuckle swings slightly to amore closed position and the two couplers then assume the relationshipshown in Fig. 5. The heel portion 22 of the knuckle carried by thecoupler on the right then engages the guard arm of the coupler at theleft in thezoneindicated at 46 in Fig. 5. The heel portion 22 of theknuckle carried by the coupler at the left engages'the guard arm 16 ofthe coupleron the right in. thesame area. Thus the heel por-. tionsengage the more "generally transverse abutment surfaces orshoulders32.0f the respective guard arms and the impact force is thus applied tothe guardarms of'both couplers. It willbe observed froma considerationof Fig. 5 that space is provided between the heel portion of eachknuckle and the improved contour of each guard arms so as to permit theheel portion of each knuckle to engage theiabutment-surfacesrorshoulders 32. Accordingly there is very little wedgingactionsuchashaszoci curred in the past'to .set up: bendingstressesurging the: guard arm of one coupler outwardlyandthus: causing: failureof the couplerthead. The improved guardarm' shape permitting theconditionshowninFig; 5 tobe; attained provides forthe distribution: ofthexstressesfover greater portions ofboth couplers. lt hasbeenifoundithat couplers providedwith the improved guard'armcone tour surface willabsorb approximately." three times: greater'impact forces or'about1,360,000 pounds*without1: rupture-of the coupler head in thecontourarea l8i-ofrthe' coupler.

The disadvantageous stable condition of two'couplers of i a prior'designengaging under similar conditions'isdiae grammatically illustrated inFig. 6. The coupler shown at the left has its'knuckle in the partlyclosed position while the knuckle ofthe coupler on the'right'is. inthefully closed position. The nose of the partly closed knuckle engagesthe nose of the other knuckle in the area indicated at 51. The heelportionof the partly closed: knuckle engages the guard arm of thecoupleratthe right; in an area indicated at 53. When both couplersare'in; the angular relationship depicted'in Fig. 6'the1impact' forceacts along the line 36 which extends between'the' butt bearing surfacesof 'the'coupler stems. Oneline of force 52 extends perpendicularly fromthecontacting surfaces at 51 and the other line of 'forcesfizextends'atright angles from the contacting surfaces at 53. These forces intersectat a point 54which lies substantiallyon .theline: 36. Line 36 passesnear the pivot'pointof the partlya': closed knuckle. In view of the factthat there; isconsiderable friction between the bearing parts .ofJthepartly closed knuckle no resultant unbalanced momentexiststto:rotate the couplers from the position shown in Fig; 6' hence a stablecondition exists. Thus the two opposing: couplers of a prior type moveinto engagement with'eaclr other without the development of aresultantforce for moving the partly closed knuckle to a more closed position.The partly closed knuckle remains in a position to be wedged betweenthenose of the closed knuckle and l the guard arm tending to bend theguard arm outwardly and tending to shift the knuckle side ofthecouplerout wardly as a result of the wedging. action on-thenose thereof.Accordingly one of the couplers'is required to absorb the impact forcein such a manner that rupturehas occurred in the arearepresentedapproximately by the line 57.

The removal of a relatively small portion ofmetalwithin the guard armcontour provides the'advantage of developing a resulting'force ashereinbefore described in connection with Figs. 4 and 5 to swing' thetwo couplers laterally as a result of an unstable condition that isdeveloped to provide for the heel portion'of-both knuckles of opposedcouplers to come into engagement with the guard arms and more. generallytransversesurfacesthereona With acouplersuch" asshown -in Fig. 1' andwithxtwm such couplers arriving in the"- condition; shownninuFigl 5 L 1.5 substantially all danger of breakage or failure in the vicinity ofthe line 57 of Fig. 6 is eliminated for normal operation of the railwayvehicles. It is to be noted that the altered guard arm contour does notchange the normal operation of the coupler.

While the invention has been described with reference to a particulartype of interlocking coupler it will be appreciated that the guard armof other couplers may be similarly shaped and other modifications andchanges may be made without departing from the spirit and scope of theinvention as set forth in the appended claims.

What I claim and desire to secure by Letters Patent is:

1. In a railway coupler, a coupler head having a contour thereon, aguard arm projecting forwardly beyond a rear portion of said contour andat one side of the coupler head, a concave surface forming a portion ofthe inner face of said guard arm generated about a vertical axis spacedlaterally of the longitudinal center of the coupler head at a distanceof approximately six and fifteen-sixteenth inches, said concave surfacemerging with a more generally straight surface in proceeding towards anose portion of the guard arm, said concave surface joining said contourin a vertically extending ridge positioned laterally of the center lineof the coupler head a distance of approximately six and fifty-sevensixty-fourth inches and forming an abutment surface laterally of saidridge generally transverse of the longitudinal axis of the coupler head.

2. In a railway coupler, a coupler head having a contour thereon, aknuckle mounted on the coupler head for swinging movements about avertical axis and being in a closed position, a guard arm on the couplerhead extending forwardly of the contour, a nose on said knuckle, aconvex heel surface on said knuckle, a vertically extending ridge onsaid guard arm positioned forwardly of the coupling line, a concavesurface forming an inner face of said guard arm forwardly of said ridgegenerated about a vertical axis positioned laterally of the center lineof the coupler head a distance greater than the lateral displacement ofsaid ridge from said center line, said concave surface extending to saidridge providing a forward facing shoulder adjacent said ridgesubstantially at right angles to said center line, the radius aboutwhich said concave surface is formed being not less than that of saidconvex heel surface whereby the heel of an opposed partly open knuckleengages only said forward facing shoulder in the vicinity of said ridgewhen the nose of the partly open knuckle is in engagement with the noseof said closed knuckle and the remainder of the convex heel of theopposed partly open knuckle cannot bear against said concave surfacewhen the nose of the partly open knuckle is in engagement with the noseof said closed knuckle.

3. In a railway coupler, a coupler head having a contour thereon, aknuckle mounted on the coupler head for swinging movements about avertical axis and being in a closed position, a guard arm on the couplerhead extending forwardly of the contour, a nose on said knuckle, aconvex heel surface on said knuckle, a vertically extending ridge onsaid guard arm positioned forwardly of the coupling line, a concavecylindrical surface forming an inner face of said guard arm generatedabout a vertical axis positioned laterally of the center line of thecoupler head a distance greater than the spacing of said ridge from saidcenter line, said concave surface extending to said ridge providing aforward facing shoulder outwardly of said ridge generally at rightangles to said center line, the radius about which said concave surfaceis developed being approximately equal to but not less than that of theconvex heel surface of the knuckle of an opposed coupler whereby theheel of the opposed knuckle in a partly open position engages only saidforward facing shoulder when the nose of the partly open knuckle is inengagement with the nose of said closed knuckle with the remainder ofthe convex heel of the opposed partly open knuckle spaced from saidconcave surface when the nose of the partly open knuckle is inengagement with the nose of said closed knuckle.

4. Two railway couplers comprising, a first and a second coupler headeach having a contour thereon, a knuckle mounted on each coupler headfor swinging movements about a vertical axis, a nose on each knuckle, aguard arm on the second coupler head extending forwardly of the contourthereof, a convex heel surface on the knuckle carried by the firstcoupler head, the knuckle on the first coupler head being in a partlyopen position and the knuckle of the second coupler head being in afully closed position as the two couplers move towards each other, avertically extending ridge on the guard arm of the second coupler headpositioned forwardly of the coupling line, a concave surface forming aninner face of said guard arm generated about a vertical axis positionedlaterally of the center line of the second coupler head a distancegreater than the lateral spacing of said ridge from said center line,said concave surface extending to said ridge providing a forward facingshoulder in the vicinity of said ridge substantially at right angles tothe center line of the second coupler head, the radius about which saidconcave surface is developed being not less than that of said convexheel surface so that said heel engages said forward facing shoulder whenthe nose of the knuckle on the first coupler is in engagement with thenose on the knuckle on the second coupler head whereby the remainder ofsaid convex heel surface cannot bear against said concave surface whenthe nose of the partly open knuckle is in engagement with the nose ofsaid closed knuckle.

References Cited in the file of this patent FOREIGN PATENTS 734,454Great Britain May 11, 1953

